Functional polymers have conventionally been widely used as resists in high resolution lithography for manufacturing LSI (large scale integrated circuits). In view of the current trends towards higher density, such resists are now being required to offer even higher resolution and higher developability. To meet these requirements, in the case of the novolak resins commonly used as resists, resolution and developability were increased by controlling the molecular weight of the polymer by means of fractionation (Japanese Tokkai Sho 62-1217542 (unexamined publication)).
Fractionation however involves a complicated procedure, and it requires a considerable time.
Recently, various chemically sensitized amplified types of resists are being studied with a view to replacing conventional resists. These resists are characterized in particular by their workability, due to the fact that they possess functional groups which can easily be eliminated by acids and to the fact that their solubility is different before and after the elimination.
From these viewpoints, styrene derivatives having excellent plasma resistance are well known, but they were unable to meet the increasingly stringent performance requirements.
Such polymers which were the main component of resists known in the art were obtained by ordinary radical polymerization or condensation polymerization, but no attempt was made to control their molecular weights or molecular weight distribution.
In this context, the Applicant carried out detailed studies of resists offering higher resolution and discovered a novel p-vinylphenoxy-dimethylphenylcarbyldimethylsilane living homopolymer having a narrow dispersion of molecular weight which led to the present invention.